NEW YORK (AFP) - Wall Street stocks finished lower on Tuesday (April 7) as a rally based in part on optimism over apparent progress in combating the coronavirus faded late in the session.

The Dow Jones Industrial Average, which was up almost 1,000 points earlier in the session, finished down 0.1 per cent at 22,653.86.

The broad-based S&P 500 shed 0.2 per cent to end the day at 2,659.41, while the tech-rich Nasdaq Composite Index lost 0.3 per cent to 7,887.26.

Financial markets have been closely monitoring grim health reports and were cheered by data showing New York's three-day average of hospitalisations had gone down.

There were also some improved data points out of Italy and other hotspots, although elsewhere the virus remains very much an untamed threat.

Many investors are girding for trading volatility until the situation becomes clearer.

The gyrations of stocks in reaction show "markets are not completely rational," said Gregori Volokhine of Meeschaert Financial Services.

"They often move on sentiment, which can be hope as much as fear."

Volokhine said investors also have been encouraged by the muscular response of policy makers in Washington and beyond to try to protect the economy from the worst devastation of the Covid-19 shutdowns.

US Treasury Secretary Steven Mnuchin said Tuesday he is asking Congress to reinforce a new small business loan programme that has been overwhelmed with applications, requesting another US$250 billion (S$355 billion) to a programme originally funded with US$349 billion.